FIG. 1 shows a conventional detector cooler design comprising:                an IR detector 1 placed in a vacuum chamber (cryostat 2) which maintains the temperature of this chamber at an operating temperature of the detector, or approximately −200° C.,        a cooling machine 3 which uses, for example, helium and supplies the cryostat with the refrigeration needed to bring its temperature (usually lower its temperature) from an ambient temperature to the operating temperature. The time needed to reach the operating temperature is designated “refrigerating time” (TMF). The overall performance is measured over a meaningful temperature range: from −173° C. to −190° C. The TMF to change from −173° C. to −190° C. is typically a few tens of seconds,        a device 4 for servocontrolling this cooling machine according to the temperature of the detector TD supplied by a sensor 8.        
The detector coolers that are used at present are fragile, heterogeneous in that no two identical detector coolers behave in the same way, and costly. The actual maintenance is limited to confirming the breakdown when it occurs, that is to say, by detecting a departure from the refrigerating time specification. The breakdown leads to unavailabilities and dissatisfaction among the users. Furthermore, the maintenance costs are high.
Consequently, there is currently a need for a system that makes it possible to overcome the abovementioned drawbacks without in any way increasing its bulk.